However, the warning doesn't cover Edinburgh, although there is a spell of heavy rain expected on Friday.
Here's the hour-by-hour forecast for Friday:
5pm: Heavy rain
6pm: Light rain
"Eastern Borders seeing the best of the drier spells. Blustery southwesterly winds. Maximum temperature 18 °C."
It's not great news if you're looking forward to a weekend spent outdoors.
Saturday is set to be a much more unsettled day with longer spells of lighter rain, with Sunday also looking wet and miserable for the majority of the day.